Research indicates that sleep does more than allow the brain to rest. The poor sleep is thought to have a severe impact on the ability to learn and remember information because the brain is being deprived of time that it needs to consolidate information which is essential to the learning process.
Current studies demonstrate that a healthy sleep produces a significant learning-dependent performance boost. Multiple hypotheses explain the possible connections between sleep and learning in humans. Healthy sleep must include the appropriate sequence and proportion of NREM and REM phases, which play different roles in the memory consolidation-optimization process.
The 'synaptic scaling' hypothesis suggests that sleep plays an important role in regulating learning that has taken place while awake, enabling more efficient and effective storage in the brain, making better use of space and energy. Research has also shown that taking an afternoon nap increases learning capacity.
After sleep, there is increased insight. This is because sleep helps people to reanalyze their memories. The same patterns of brain activity that occur during learning have been found to occur again during sleep, only faster. One way that sleep strengthens memories is by weeding out the less successful connections between neurons in the brain. This weeding out is essential to prevent overactivity.
The brain compensates for strengthening some synapses (connections) between neurons, by weakening others. The weakening process occurs mostly during sleep. This weakening during sleep allows for strengthening of other connections while we are awake. Learning is the process of strengthening connections, therefore this process could be a major explanation for the benefits that sleep has on memory.
In motor skill learning, an interval of sleep may be critical for the expression of performance gains; without sleep these gains will be delayed. Sleep has also been directly linked to the grades of students.
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